To obtain a flexible foam adequately stabilized against collapse and having a good closed-cell structure, it is known to add a surfactant. A flexible foam having a high number of closed cells, however, leads to shrinkage. One means generally employed to open the cells and eliminate foam shrinkage is to mechanically treat the foam by crushing with rollers, with a vacuum technique, or by lancing. It would be desirable, however, to produce a surfactant that stabilizes the foam against collapse while opening the cells of the foam without the necessity for mechanical treatment.
The elimination of foam shrinkage by opening the cells using new types of surfactants was the topic of a paper by D. R. Battice, et al., New Cell Opening Surfactants For Molded High Resiliency Polyurethane Foam, 30th Annual Polyurethane Technical Marketing Conference, Oct. 15-17, 1986, pp. 145-148. The new surfactants that promoted good cell drainage and eliminated foam shrinkage were identified as X2-5249 and X2-5256, both silicone-based and manufactured at the time by Dow Corning. These surfactants successfully reduced foam shrinkage over a previous Dow Corning.RTM. 5043 surfactant.